CVE-2025-53504
📋 TL;DR
Group-Office versions before 6.8.119 and 25.0.20 contain a cross-site scripting (XSS) vulnerability that allows attackers to execute arbitrary scripts in users' web browsers. This affects all users of vulnerable Group-Office installations, potentially compromising their sessions and data.
💻 Affected Systems
- Group-Office
📦 What is this software?
Group Office by Group Office
Group Office by Group Office
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, perform actions as authenticated users, redirect to malicious sites, or install malware through the user's browser.
Likely Case
Session hijacking, credential theft, or defacement of the Group-Office interface through injected content.
If Mitigated
Limited impact if proper input validation and output encoding are implemented, though some script execution might still occur.
🎯 Exploit Status
Exploitation requires the attacker to inject malicious scripts into user-accessible areas of Group-Office, typically through crafted input that isn't properly sanitized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.8.119 or 25.0.20
Vendor Advisory: https://www.group-office.com/
Restart Required: No
Instructions:
1. Backup your Group-Office installation and database. 2. Download the patched version (6.8.119 or 25.0.20) from the official Group-Office website. 3. Follow the upgrade instructions provided by Intermesh BV. 4. Verify the upgrade completed successfully.
🔧 Temporary Workarounds
Implement Content Security Policy (CSP)
allAdd a Content Security Policy header to restrict script execution to trusted sources only.
Add 'Content-Security-Policy: default-src 'self'; script-src 'self'' to your web server configuration
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block XSS payloads in HTTP requests.
- Disable user input fields that accept HTML or JavaScript where possible, or implement strict input validation.
🔍 How to Verify
Check if Vulnerable:
Check the Group-Office version in the administration panel or by examining the software files. Versions below 6.8.119 or 25.0.20 are vulnerable.Check Version:
Check the version in Group-Office admin interface under 'System' > 'About' or examine the version.php file in the installation directory.Verify Fix Applied:
Confirm the version is 6.8.119 or higher (for version 6 series) or 25.0.20 or higher (for version 25 series) in the administration panel.📡 Detection & Monitoring
Log Indicators:
- Unusual script tags or JavaScript in user input logs
- Multiple failed login attempts followed by successful login from different IP
Network Indicators:
- HTTP requests containing suspicious script tags or JavaScript payloads
- Unexpected redirects to external domains
SIEM Query:
source="groupoffice_logs" AND ("<script" OR "javascript:" OR "onerror=" OR "onload=")